SCD4808N Rev B

FEATURES

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ACT4808N Dual Transceiver meets MIL-STD-1553A & B, Macair A3818, A5690,

A5232 and A4905 specs

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New Low Power Model

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Operates with ±12V to ±15V & +5V Power Supplies

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Voltage source output

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Plug-in or Flat Package

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Monolithic construction

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Designed for commercial, industrial and aerospace applications

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MIL-PRF-38534 compliant devices available

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Aeroflex-Plainview is a Class H & K MIL-PRF-38534 manufacturer

GENERAL DESCRIPTION

The Aeroflex-Plainview ACT4808N is a monolithic transceiver design which provides full compliance with Macair

(A-3818, A-4905, A-5232 and A-5690) and MIL-STD-1553A/B data bus requirements and can be considered a

"Universal" Transceiver.

The dual channel transceiver performs the front-end analog function of inputting and outputting data through a

transformer to the MIL-STD-1553 or Macair data bus.

Design of this transceiver reflects particular attention to active filter performance. This results in low bit and word

error rate with superior waveform purity and minimal zero crossover distortion. The ACT4808N series active

transmit filter design has additional high frequency roll-off to provide the required Macair low harmonic distortion

waveform without increasing the pulse delay characteristics significantly.

Efficient transmitter electrical and thermal design provides low internal power dissipation and heat rise at high as

well as low duty cycles. The receiver input threshold is set Internally.

TRANSMITTER

the data bus signal produced is 7.0 Volts typical P-P at Point A-A’ (See Figure 3 or 4)

. When both DATA and DATA inputs

are held low or high, the transmitter output becomes a high impedance and is “removed” from the line. In addition, an

overriding “INHIBIT" input provides for the removal of the transmitter output from the line. A logic “1” signal

applied to the “INHIBIT” takes priority over the condition of the data inputs and disables the transmitter (See

Transmitter Logic Waveform, Figure 1).

The transmitter utilizes an active filter to suppress harmonics above 1 MHz to meet Macair specifications A-3818,

A-4905, A-5232 and A-5690. The transmitter may be safely operated for an indefinite period at 100% duty cycle into

a data bus short circuit (Point A-A’). The Transmitter may be safely operated for an indefinite period with the 1553

bus (Point A) short circuited at 100% duty cycle.

RECEIVER

The Receiver section accepts bi-phase differential data at the input and produces two TTL signals at the output. The

outputs are DATA and DATA, and represent positive and negative excursions of the input beyond a pre-determined

threshold (See Receiver Logic Waveform, Figure 2).

The internal threshold is nominally set to detect data bus signals exceeding 1.10 Vp-p and reject signals less than 0.6

Vp-p when used with a 1:1 turns ratio transformer (See Figure 4 for transformer data and typical connection).

A low level at the Strobe input inhibits the DATA and DATA outputs.

ACT4808N Dual Transceivers

Standard Products

www.aeroflex.com/Avionics

May 25, 2005

for MACAIR (A3818, A4905, A5232, A5690) and MIL-STD-1553A/B